This research proposal is designed to investigate the biochemistry of alpha-D-galactopyranosyl units in animal glycoproteins. We shall study the distribution, biosynthesis and degradation, and possible role of this carbohydrate unit in biological systems using the Ehrlich ascites tumor cell as our model system. The complete chemical structure of the carbohydrate moiety of a family of alpha-D-galactosyl-containing glycoproteins from Ehrlich tumor cell plasma membranes will be determined. We will study the mode of incorporation of alpha-D-galactosyl groups from UDP-galactose into Ehrlich cell plasma membrane glycoproteins with special attention to the possible participation of lipid-linked galactose intermediates, e.g. dolichyl phosphate galactose. We will isolate, characterize, and investigate the possible role of a lysosomal alpha-D-galactosidase, isolated from the Ehrlich cell, in the biodegradation of membrane alpha-D-galactosyl-containing glycoproteins. We will also investigate immunological strategies for regulating Ehrlich tumor cell growth in Swiss white mice. These studies will involve immunization with membrane glycoproteins and a synthetic carbohydrate-protein conjugate. Finally, we will carry out preliminary characterization of epithelial basement membrane from murine kidney and of 3T3 cells to confirm our discovery of the presence of alpha-D-galactosyl groups.